--- title: "Diarmuid Fionntain O'Scannlain | KnowJudges" canonical: "https://knowjudges.com/kyj/judge/diarmuid-fionntain-o-scannlain" page_type: "judge_profile" updated: "2026-10-09" --- # Diarmuid Fionntain O'Scannlain U.S. Court of Appeals for the Ninth Circuit · U.S. Circuit Judge ## Profile - Court: U.S. Court of Appeals for the Ninth Circuit - State: National federal courts - Role: U.S. Circuit Judge - Service status: senior - Last verified: 2026-07-25 ## Summary Official statewide and applicable court procedural guidance applies to this judge. ## Biography ### Professional career - Judge, Court of Appeals for the Ninth Circuit, 1986-present - Chairman, Advisory Panel to the Secretary of the U.S. Department of Energy, 1983-1985 - Director, Oregon Department of Environmental Quality, 1973-1974 - Deputy attorney general, State of Oregon, 1969-1971 - Judge of the United States Court of Appeals for the Ninth Circuit - Current Role: Senior Judge, U.S. Court of Appeals for the Ninth Circuit, chambers in Portland, Oregon - As a Ninth Circuit judge, O’Scannlain participated in over 6,000 federal cases and authored hundreds of opinions covering constitutional, international, securities, administrative, and criminal law ### Education - University of Virginia School of Law — Judicial Process in — LL.M. (1992) - B.A. — St. John’s University, a J.D. in 1963 from Harvard Law School, (1957) ### Additional information - Oral History of Distinguished American Judges, Institute of Judicial Administration, New York University School of Law, 2020. - Ninth Circuit until taking senior status on December 31, 2016. - He has been active in judicial administration, serving as chair of the International Judicial Relations Committee of the U.S. Judicial Conference (2010–2015) and as chair of the Federal Judicial Center’s Advisory Committee on Appellate Judge Education. - He also holds honorary doctorates from the University of Notre Dame (2002), Lewis & Clark College (2003), and the University of Portland (2011). - In 2007, Pope Benedict XVI conferred the Order of Saint Gregory the Great upon him and his wife. - Nominated by President Ronald Reagan on August 11, 1986, O’Scannlain was confirmed by the Senate on September 25, 1986, and commissioned on September 26, 1986. - Private practice, Portland, Oregon, 1965-1969, 1975-1986 - Team leader, President's Private Sector Survey on Cost Control (Grace Commission), 1982-1983 - Consultant, Office of the President-Elect of the United States, 1980-1981 - Before joining the federal judiciary, O’Scannlain served in the U.S. Army Reserve, JAG Corps from 1955 to 1978, retiring as a major. - Public utility commissioner, State of Oregon, 1971-1973 - Tax attorney, Standard Oil Company of New Jersey and New York City, 1963-1965 - Date of birth: 1937-01-01 - He also held advisory roles for the U.S. President-Elect, the U.S. Department of Energy, and the Northwest Power Planning Council. - O’Scannlain has testified before the Senate and House Judiciary Committees, chaired the ABA’s Judicial Division, and taught at Lewis & Clark Law School and numerous appellate seminars. - Birth place: New York, NY ## Before you appear - Read the judge-specific standing order first when one is listed. - Check the docket and case orders for requirements that supersede broader guidance. - Confirm current remote-access and courtroom technology arrangements before the proceeding. ## Courtroom Rules ### appellate oral argument Scope: courtwide In federal courts of appeals, oral argument is allowed unless a three-judge panel unanimously finds one of Rule 34's specified grounds for dispensing with it; the clerk provides the date, time, place, and time allocation. Evidence excerpt: Oral argument must be allowed in every case unless a panel of three judges who have examined the briefs and record unanimously agrees that oral argument is unnecessary [Federal Rule of Appellate Procedure 34, Oral Argument](https://www.uscourts.gov/forms-rules/current-rules-practice-procedure/federal-rules-appellate-procedure) Source checked: 2026-07-26 ## Sources - [Official profile](https://www.fjc.gov/node/1385926) - [Official roster](https://www.fjc.gov/node/1385926) - [Federal Judicial Center biography](https://www.fjc.gov/node/1385926) - [CourtListener judicial biographical directory](https://www.courtlistener.com/person/2458/diarmuid-fionntain-oscannlain/) - [Federal Rule of Appellate Procedure 34, Oral Argument](https://www.uscourts.gov/forms-rules/current-rules-practice-procedure/federal-rules-appellate-procedure) - [CourtListener judicial biographical directory](https://www.courtlistener.com/person/2458/diarmuid-fionntain-oscannlain/) - [Judge Diarmuid Fionntain O'Scannlain](https://www.fjc.gov/node/1385926) - [Wikidata: Diarmuid O'Scannlain](https://www.wikidata.org/wiki/Q5271932) ## JSON-LD ```json { "@context": "https://schema.org", "@graph": [ { "@type": "WebPage", "@id": "https://knowjudges.com/kyj/judge/diarmuid-fionntain-o-scannlain", "url": "https://knowjudges.com/kyj/judge/diarmuid-fionntain-o-scannlain", "name": "Diarmuid Fionntain O'Scannlain | KnowJudges", "description": "Diarmuid Fionntain O'Scannlain, U.S. Court of Appeals for the Ninth Circuit. Source-linked judicial identity, courtroom procedures, and presentation guidance.", "dateModified": "2026-10-09", "isPartOf": { "@id": "https://knowjudges.com/#website" }, "mainEntity": { "@id": "https://knowjudges.com/kyj/judge/diarmuid-fionntain-o-scannlain#judge" } }, { "@type": "Person", "@id": "https://knowjudges.com/kyj/judge/diarmuid-fionntain-o-scannlain#judge", "name": "Diarmuid Fionntain O'Scannlain", "url": "https://knowjudges.com/kyj/judge/diarmuid-fionntain-o-scannlain", "jobTitle": "U.S. Circuit Judge", "worksFor": { "@type": "GovernmentOrganization", "name": "U.S. Court of Appeals for the Ninth Circuit" }, "sameAs": [ "https://www.fjc.gov/node/1385926", "https://www.courtlistener.com/person/2458/diarmuid-fionntain-oscannlain/" ], "birthDate": "1937", "birthPlace": "New York, NY", "alumniOf": [ { "@type": "EducationalOrganization", "name": "St. John's University" }, { "@type": "EducationalOrganization", "name": "Harvard University" }, { "@type": "EducationalOrganization", "name": "University of Virginia School of Law" } ] }, { "@type": "BreadcrumbList", "itemListElement": [ { "@type": "ListItem", "position": 1, "name": "KnowJudges", "item": "https://knowjudges.com/kyj" }, { "@type": "ListItem", "position": 2, "name": "National federal courts", "item": "https://knowjudges.com/kyj/state/national-federal-courts" }, { "@type": "ListItem", "position": 3, "name": "Diarmuid Fionntain O'Scannlain", "item": "https://knowjudges.com/kyj/judge/diarmuid-fionntain-o-scannlain" } ] } ] } ```